The ex-Army Royal Green Jackets captain’s comments come after a female officer was kicked and almost fell into the path of a passing double-decker bus in Merton, south London, as an onlooker filmed the event. Several cars drove past without stopping to help during the attack on two officers. Metropolitan Police Federation chairman Ken Marsh has warned officers may be forced to let violent suspects go if the public do not support them more. Mr Ellwood, who rushed to administer medical attention to PC Keith Palmer during last March’s Westminster terrorist attacks, backed calls for the British public to step up to the plate to deter criminals.

He told Express.co.uk: “Unfortunately there is a risk aversion that has stepped in to society whereby there is a fear of stepping forward.

“We do need to challenge that.

“When it is clear that mass strength and numbers can easily alter the outcome of a situation by people stepping forward then absolutely that should be something that goes through our minds.

“At the moment, we have reached the point whereby we fast track to a conclusion not even to consider stepping forwards.

“I believe the pendulum has swung too far with this non-interference and with the consequences we see.”

He added: “The trouble with where we now are is the bad people, the criminal, the terrorist plays on the fact nobody will step forward.

“They are reliant on the fact that the only back up likely to emerge is emergency services themselves, which may take some time to get there.

“Of course, you don’t want to endanger anyone. But in this situation here, the human instinct should be to want to intervene to prevent an attack from taking place.”

Following last Saturday’s attack, Martin Payne, 20, from Croydon, was charged with ABH and assault on an emergency worker.

Two other suspects remain at large.

Metropolitan Police assistant commissioner Sir Steve House spoke out on Tuesday and called on people to help officers “if they can safely do so”.

Mr Ellwood was widely praised for battling to try and save PC Palmer’s life outside Parliament in March last year.

Photos showed Mr Ellwood at the scene, where he gave CPR to PC Palmer after he was stabbed by Islamist terrorist Khalid Masood.

The MP for Bournemouth East stressed the public should not feel obliged to step in if they feel threatened in violent situations, but people nevertheless had a “duty” to help in some way.

Mr Ellwood said: “I am sad to see people walk on by. Even if you walk on by you still can help.

“When we talk about first responders, the first responders to any situation are those who happen to be at the location at the time.

“They have a duty to society, to their community to help in some way. It may be just shouting.There are many ways you can affect the outcome for the better. Walking away is not one of them.

“We really must ask ourselves where society is going when we simply walk on by.”